17 Fascinating Facts You May Not Know About Horses

Horses and humans have a long history together. But how much do you really know about these incredible animals?

1. Horses are pretty historical.
2. There are hundreds of horse breeds.
3. Horses have huge eyes.
4. They have some unexpected relatives.
5. Horse hooves are sensitive.
6. Horses eat a lot ...
7. ... But they can’t vomit.
8. There’s a history to the hand.
9. Horses are emotional creatures.
10. The ribbons on their tails mean something.
11. Most horses are domestic.
12. A knight likely had many different horses.
13. Horses barely sleep.
14. The Mounties haven’t actually ridden horses on the job in a while. 
15. Arabian horses have a few unique features.
16. Australia used to be horse-less.
17. It can take a lot to put them in a movie.

Horses are pretty historical.

Cave art gives us the first documentation of horses, which were likely domesticated in Eurasia some 10,000 years ago. They appear in mythology from China to Greece and have been relied on for travel, farming, and other purposes by many cultures for thousands of years. Horses have also been involved in almost every documented war. 

There are hundreds of horse breeds.

Seriously. Hundreds. Depending on whom you ask, this list may or may not include ponies (which are not quite the same as horses). They can be divided into several groups, including light horses, heavy horses, and feral horses.

Horses have huge eyes.

Horses have the largest eyes of any mammal that lives on land. They’re capable of moving them independently and, because their eyes are on the sides of their head, they have nearly 360 degree vision. However, they have two blind spots—one directly in front of them, and one directly behind.

They have some unexpected relatives.

They’re distantly related to rhinoceroses and tapirs. They’re also related to donkeys and zebras.

You May Also Like ...

• What’s the Difference Between Horses and Ponies?
• The Origins of 12 Horse-Related Idioms
• How ‘Black Beauty’ Changed the World For Horses

Add Mental Floss as a preferred news source!

Horse hooves are sensitive.

A horse’s hooves are exceptionally complex and sensitive—which is why many need to wear shoes. When the horse puts pressure on its hoof, the blood shoots up its leg into the veins, thus acting like a pump. In addition, the hooves are just like human nails: Their hooves have to be regularly trimmed and maintained to keep them from causing the horse any pain or discomfort.

Horses eat a lot ...

Horses eat different amounts depending on their size, but they’re all good at putting it away. Like humans, horses will eat not only to meet daily needs, but because food tastes good. So they keep on eating. Some estimates say that a horse that weighs 1200 pounds can eat seven times its weight in a year.

... But they can’t vomit.

Because of their inability to regurgitate food, digestive problems can be fatal. As such, colic is a leading cause of death in horses.

There’s a history to the hand.

A hand unit is 4 inches, and yes, it was originally based on the male human hand. The measurement was standardized by King Henry VIII in 1541 as a simple way to measure horses. The hand unit is the length of either a clenched fist or the breadth of the hand (although there’s some debate over whether or not a thumb should be included). Because most of the time a human hand isn’t exactly 4 inches by any of those measures, we now have tape measures and measuring sticks specially designed to gauge horse height and weight.

Horses are emotional creatures.

Horses are extremely adept at expressing their emotions through their body language. They’re also highly perceptive to human emotions and tend to mirror them. Thus, if you’re in a good mood, your horse will most likely be amiable and easier to handle. But if you’re anxious or angry, then your mount will pick up on that, too, which could spell for a less-than-pleasant ride.

The ribbons on their tails mean something.

If you see a red ribbon on a horse’s tail, you should stay back: It means the horse kicks. Red isn’t the only color you might see, though.

• A white ribbon means a horse is for sale
• A pink ribbon signals the horse is a mare
• A blue or yellow ribbon denotes a stallion.
• A green ribbon tells you a horse is younger and probably inexperienced.

Not every equestrian uses ribbons, though.

Most horses are domestic.

However, there are feral horses out there whose ancestors were tamed animals. For example, North American mustangs are the descendants of Iberian horses brought over by Spanish explorers centuries ago.

The Przewalski’s horse is the only remaining truly wild horse. The breed has never been tamed and—before its population dwindled—it used to exist between Eastern Europe and Asia. It is currently on the list of critically endangered animals.

A knight likely had many different horses.

To be a knight in feudal England, you had to be born into a royal family or earn the honor in battle. That’s usually how knights afforded to have several horses for several different reasons. The strongest horses would likely be warhorses, whereas smaller horses would be used for travel or general purposes.

Horses barely sleep.

Horses usually sleep only 3 to 4 hours a day, and not consecutively—they actually sleep in short bursts. However, they are capable of experiencing two different kinds of sleep, SWS (short wave sleep) and REM (rapid eye movement). In addition, they can sleep standing up because of the way their joints can lock.

The Mounties haven’t actually ridden horses on the job in a while. 

The Royal Canadian Mounted Police is the national police force in Canada. They’re famous for their nifty uniforms and the fact they ride horses. The only problem? Special ceremonies are really the only time they are actually on horseback, because most mounted police forces are now local forces. Regardless, the horses have to go through special training.

Arabian horses have a few unique features.

Compared to other horse breeds, some Arabian horses have one less rib bone and one fewer vertebra. Some legends say they were created by Allah from wind.

Australia used to be horse-less.

The first horses arrived in Australia in 1788 when a British fleet brought them to Sydney. No indigenous horse remains or fossils have ever been found in Australia.

It can take a lot to put them in a movie.

• There are a lot of rules governing the handling of animals on a movie set: For a movie to be able to display “no animals were harmed” at the end of a production, the creatures must have been handled by people who have proper training.
• Representatives from the American Humane Society must supervise “intense action” such as rodeo scenes.
• Horses shouldn’t use stairs, which they have difficulty navigating.
• They must be held a safe distance from filming when they’re not on camera.
• If you fire a weapon while on a horse, it must be held at a certain angle in order to prevent the horse from being injured by powder burns.

There's a lot more, too. If you want to check it out, the Humane Society has published an exhaustive list of regulations.

A version of this story originally ran in 2015; it has been updated for 2025.